Honestly, I was prepared for a letdown whoever they cast anyway. There isn't really a Hollywood actress that is beautiful, curvy enough and also a convincing ass-kicker to be Wonder Woman. Only someone like Gina Carano would do it for me.
Carano seems a popular choice. I've heard pretty good things about her in Haywire, but never actually seen any of her movies. The fact that she's been an honest to God MMA fighter, and has the physique certainly would have lent something to the role.
Instead they cast a stick figure. Height, ultimately, is unimportant. That can be faked (most male action stars are pretty short apparently). She can hit the gym and put on muscle, but she can't change her frame. She's an ectomorph. You can only pile so much muscle onto a twig...